TL;DR: Define your needs first (what you want the notes for), then you'll find how to make them effortless to take them. Less friction and motivation is what create habits.

---

It's all depends on your need. Only you can devise a suitable system that will keep you taking notes. As for me, I realized that while I have good memory, what I retain was a bird view. I recall by "revisiting" the concepts again through whatever contextual information I stored (the layout of the page, the place I was, the logical reasoning,...) I did good in school, but mostly because the exams reminded me of the books, and the questions surfaced the answer (I was not great at reciting).

I found I was forgetting key information about some stuff, because I was too busy understanding it (trying to make a reasoning model about it) that I was skipping over information. Any problem solving session needed research and that usually means a lot of googling. But search engines have not been good lately (seo garbages), so I decided to keep everything closer. My notes system is mostly for keeping interesting facts about things I read, did, or thought. Spaced Repetition Systems (SRS) could work, but I was never fan of learning things by heart (again school) and believed in understanding and practicing (you only do what you like to do or need to do, so that act as a filter of what's important)

So I keep hoards of PDF, have two database of interesting links (Things I need to read and things that are interesting). My notes are tidbits of information: Documentation, Project Planning, Books extracts, summary. I only do the barest of organization (I use Bear which use tags and can do full-text search). But what is more important is revisiting, and rewriting. Everything is an idea and a new exposition can spark new ones. I'm not memorizing anything, they're just there for references and brainstorming.

---

As for the note taking itself, if it's a short piece (web articles), I try to read it as a whole first, then go back to take quotes of what I liked (and the source). Maybe I add a short observation. For longer piece of science fiction, I convert it to PDF (because of better annotation support) and just highlight what elicits a reaction. Then I reread the chapter (or two or three if they're short) and only focus on what I marked the first time. I either copy the whole thing over, dismiss it, or do a short summary. If the book is a map, what I do is trace the interesting landmarks and trace a route through them. As I said before, I don't care about memorizing, I just note what was interesting/important for me in the book. Another reread later, and I'd probably highlighted different things.

> Another problem I run into is that when I’m very attentive to a task or piece of information and want to take some note on it or reference notes from elsewhere, switching contexts to my notes is disruptive.

My advice would be to make it quick. If I'm reading on my computer. I'd copy-paste the interesting fact (just create a new note and add the date somewhere, maybe). If it was a physical book, I'd just grab a piece of paper, or my phone to take a picture. If it was on my phone, I screenshot it. I just want to store it quickly as possible and get back to it later. If I want to reference something, but the current task is reading and not collating information. I just add a quick task on the note (ex. <this> reminds me of <that>, check it out".